Sprue-former



E. I. ROSHEIM.

SPRUE FORMER.

APPLICATION FILED APR. II. I92I.

Patented Aug. 16, 1921.

InvQZtal a sprue former UNITED STATES ELLIN G I. ROSHEIM, OF ROLAND,IOWA.

SPRUE-FORMER.

Application filed April 11, 1921.

To all whom it may concern:

e it known that I, ELLING I. ROSHEIM, a citizen of the United States,and a resident of Roland, in the county of Story and State of Iowa, haveinvented a certain new and useful sprue-Former, of which the fol lowingis a specification.

The object of my invention is to provide of very simple, durable andinexpensive construction.

More particularly, it is my object to provide a sprue former, havingparts so constructed and arranged as to make possible the ready and easycentering of the pattern with relation to the ring or form in which themold is made.

With these and other objects in view, my invention consists in theconstruction, arrangement and combination of the various parts of mydevice, whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claims, and illustrated in theaccompanying drawings, in which:

I igure 1 shows a top or plan view of a sprue former embodying myinvention.

ig. 2 shows a side elevation of the same, illustrating one of themovable parts in a certain position.

Fig. 3 shows a vertical, transverse, sectional view of a sprue former,showing the movable parts in another position.

Fig. at shows an inverted plan view of the device; and

Fig. 5 shows a side elevation of a wax pattern, showing a pin insertedtherein.

In preparing a filling or inlay for teeth, it is the common dentalpractice to first prepare the cavity, then fill the cavity with wax formaking a pattern for the casting of the inlay or filling.

In Fig. 5, I have shown a tooth l0 indicated generally by the referencenumeral 10. having a cavity in which the wax pattern 11 has been made.After the pattern has set slightly, it must be removed from the cavity.

his is accomplished in various ways, but the preferable way is to insertthe point of a pin 12 into the wax pattern 11 adjacent to one sidethereof,.as illustrated for instance in Fig. 5.

The pin 12 should be inserted parallel with the longitudinal axis of thetooth. This method of inserting the pin for pulling off the wax patternis much preferred by many members of the profession.

Specification of Letters Patent.

Patented Aug. 16, 1921. Serial No. 460,403.

inserted, as just meninto the middle part of the pattern, after thepattern has been removed from the tooth he pin 12 is position in thehole in dome-shaped member 13 of a sprue former 14. of a base, haw mg inits upper surface a dome-shaped portron l3, surrounded by a channel 15,having a flat annular bottom portion 16.

After the pattern has been mounted on the sprue former, the next step isto place a rin or tubular member 17, shown by dotted lines in Fig. 3, onthe sprue former, as shown in and thereafter the ring is filled with ecomposition from which the mold is made.

It is desirable that the pattern 11 be substantially at the diametricalcenter of the shaped member 13. In former, the hole is made deep enoughsimply to form a socket and support for the pin 12. provide an bottom ofthe sprue former 14.

I secure to the bottom of the sprue former,

12. The sprue former is a spring 21 adapted to stand adjacent to thelower end of the hole 19 and projecting slightly beyond the periphery ofthe sprue former, as at 21.

The hole 19 is of such size as to permit a pin 22, similar to the pin 12to slide freely therein.

In the use of my improved sprue former, the pin 22 is inserted in thehole 19 and the spring 21 is pressed downwardly slightly until the upperend orpoint of the pin 22 is below the junction of the hole 20 with thehole 19. v I

1'preferablyprovide in connection with my sprue former, a pin 12 havinga flat side 7 preferably formed with an upwardly projecting member, suchfor example as the lug 2%, adapted to coact with a notch in the ring,which lug is shown in Fig. 3

' The pin 12 with the pattern 11 or 18, as

l the case may be, mounted thereon, is inserted in inverted positionfrom hole 20.

The spring 21 is depressed to permit the pin 12 to slide freely inthehole 20. The pin 12 is raised or lowered until the pattern is inposition to be properly centered in the ring 1'7, whereupon the spring21 is released and the pin 22' will be forced into engagement with thepin 12, and will hold the pin 12 by frictional engagement in theposition to which said pin 12 hasbeen adjusted.

' It will be seen thatif I have a large pattern, the pinf12 may be movedfarther upwardly in order to centerthe pattern, and if I have a smallpattern, the pin 12 may be moved farther downwardly, as illustrated resaectively in Figs. 3 and 2.

y lowering the spring 21 slightly, the pin 22 may be made to drop awayfrom the pin 12 for permitting the pin 12 to be adjusted readilylongitudinally in the hole 20.

After the pattern has been mounted on the sprue former it may bepainted. In this connection, it will benoted that because the pin 12isgripped in. the sprue former, the latter forms a holding device forthe pin which makes for convenience and ease in the painting operation.

This is important where a quick method above into the of making a moldis involved.

By providing the pin 12 with the flat side 12*, it is possible toarrange the flat side 12 in a certain position withrelation to thepattern in all instances. This position should be such that the flatface will be engaged by the pin 22 when the pattern is mounted on thesprue former.

The use ofthe pin 12 with the fiat side 12" affords a convenient way foralways arranging the pattern in a certain position in the mold, so thatthe user can readily determine the location off'the extreme edges ofthepattern in the mold. This location is facilitated and itsdetermination made easy by the notch in the ring, which coacts with thelug 24 of the sprue former. That is to say, the user of my sprue formermay always readily determine the location of the extreme It will be seenthat my sprue former is very simple and of inexpensive construction,

and yet it permits the easy and quick adjustment of the pattern when thepinis in- I serted therein in the manner illustrated in Fig. 5 withrelation to the ring 17 for centering the pattern therein. 7 I

Some changes may be madein the construction and arrangement ofthe partsof my improved sprue formerwithout departing from the real spirit andpurpose of my invention, and it is my intention to cover by my claims,any modified forms of structure or use of mechanical equivalents, whichmay be reasonably included within their scope.

1 claim as my invention:

1. A sprue former having a central upper dome-shaped member with achannel surrounding said dome-shaped member, said dome-shaped memberhaving an opening inclined from its upward central portion downwardlyand away therefrom, and means for engaging a pin inany position of thelongitudinal adjustment of said pin in said opening. 7 V v 2. A sprueformer having a central upper domesl1aped member with a channelsurrounding said dome-shaped member, said dome-shaped member having anopening inclined from its upward central portion downwardly and awaytherefrom, and means for engaging a pin in any position of thelongitudinal adjustment of said pin in said opening, said meanscomprising a slidable member adapted to frictionally engage a pinreceived in said opening, and means for yieldably holding said slidablemember in engagement with a pin in said opening.

3. A sprue former having a central upper dome-shaped member with achannel surrounding said dome-shaped member, said dome-shaped memberhaving an opening inclined from its upward central portion downwardlyand away therefrom, and menas for engaging a pin in any longitudinalopening, said means comprising a slidably mounted pin, having one endprojecting from the body of saidsprue former and the position of theadjustment of said pin in said other end arranged adjacent to saidopening,

and a spring adapted to engage the outer having another openingextending vertically end of said second pin for holding saidsecdownwardly from the upward central part 0nd pin in engagement with apin in said of said convex portion through the body of opening. saidsprue former, a pin slidably mounted 5 i. A sprue former having a bodyformed in said second opening, a spring secured to 15 with central upperconvex portion sursaid sprue former and arranged to engage rounded by achannel, said sprue former the lower end of said pin. having an inclinedopening extending from Des Moines, Iowa, April 1, 1921. the upper centerpart of said convex portion 10 downwardly and laterally, said sprueformer ELLING I. ROSHEIM.

